21.5 Regular Expressions

A regular expression (or regexp) is a pattern that describes a whole class of strings. A full description of regular expressions and their syntax is beyond the scope of this manual; an introduction can be found in the Emacs manual (see Syntax of Regular Expressions), or in many general Unix reference books.

If your system does not include a POSIX regular expression library, and you have not linked Guile with a third-party regexp library such as Rx, these functions will not be available. You can tell whether your Guile installation includes regular expression support by checking whether the *features* list includes the regex symbol. If so, you can safely do:

     (use-modules (ice-9 regex))

This enables the complete support described in this section.

• Regexp Functions: Functions that create and match regexps.
• Match Structures: Finding what was matched by a regexp.
• Backslash Escapes: Removing the special meaning of regexp meta-characters.

[FIXME: it may be useful to include an Examples section. Parts of this interface are bewildering on first glance.]